ISO DIS 21360-4

Description / Abstract: This International Standard in conjunction with ISO 21360-1 specifies methods for the measurement of performance characteristics of turbomolecular vacuum pumps. It is applicable to all sizes and all types of turbomolecular vacuum pumps

— with mechanical or magnetic bearings, and

— with or without an additional drag stage(s) or other pumping stages on the shaft

— with one or more inlet ports

Since turbomolecular vacuum pumps are backed by primary pumps, their performance cannot be completely defined by the volume flow rate curve; also the backing pressure of the turbomolecular vacuum pump is important to the performance.

The following information completes the performance characteristics:

— information about possible throughputs and backing pressure of the turbomolecular vacuum pump

— the compression ratio curve (compression ratio vs. backing pressure of turbomolecular vacuum pump)